1. Technical Field of the Invention
The present invention relates to a print control system and a print control method and more particularly to a print control system and a print control method for efficiently printing out at a plurality of printers connected to a network in response to print requests from print instruction systems of client systems connected to the network.
2. Description of the Related Art
While construction of a network system increases rapidly, the number and quality of printers that can be used by the users improve with high functions and low costs of printers in recent years; a printing system comprising various printers connected to a network for operating the printers in parallel becomes pervasive. However, when the printers connected to the network are available, often they are not necessarily used efficiently. On the contrary, to efficiently use the printers, some restriction or load, such as new operation required for setting specification of the printer to be used, is imposed on the users.
Problems in a conventional general print control system using printers connected to a network to execute print processing are described on the following topics:
(i) Selection of printer with light load
In the conventional system, the processing time of jobs is predicted with respect to all printers as output destination candidates and a print request is issued to the printer whose load is estimated to be the lightest from the prediction result. In this method, however, it is hard to calculate precise load and if the estimated load differs largely from the actual load, the load on the printer is furthermore increased.
(ii) Simultaneous output to printers
In the conventional system, the same print job is issued to all printers as output destinations and all print objects required for print processing are also stored in the printers. In this method, however, print jobs and print objects are all managed in the printers, thus all printers need to provide resources uniformly and it is difficult to generate reliable print jobs for all printers.
(iii) Selection of optimum printer for printing out
In the conventional system, an optimum printer for print job processing is selected based on information on all printers as output destination candidates. In this method, however, printer information required for determining the optimum printer needs to be managed intensively and if a new printer is added or change in the printer operation state such as toner out occurs, the corresponding information needs to be updated whenever necessary. Further, in determination processing for selecting the optimum printer, if new print processing becomes available, a new expression for adaptation evaluation concerning the new print processing needs to be built in the determination processing.
(iv) Changing printers for printing out
In the conventional system, if some trouble occurs in the printer executing a print job processing, the print job is transferred to another operating printer for changing the output destination as a method of changing the printer for performing the print job processing. In this method, however, whenever printer trouble occurs, the print job is transferred, thus load on the network increases and at the worst, if trouble occurs consecutively in the printer to which the print job is transferred, fruitless network traffic is generated and load on all printers is increased.